https://www.youtube.com/watch?v=UqLI1xKc-L4
This is why autists are fantastic, been curious about this for awhile and yeah, any of us who give a shit about the state of games should not be installing modern multiplayer games at all at this rate. I would not be shocked if even Valve get desperate about the cheaters in their games and they go all in on anti-cheat spyware. Alternatively they may end up officially partnering with face-it.
TLDR: It's worth than anyone thinks, this video gives context and detail.
What OP is worrying about is Valve reworking VAC into a kernel anticheat. Right now VAC is a usermode anticheat based around detecting signatures of anticheat programs/signs of tampering with the game(sometimes overdoing it as AMD users were flagged as cheaters when AntiLag+ was released with a driver update, though those bans were reversed).
They already added it to League, but only to the Windows version. The macOS client uses "an alternative version"(though I presume once Apple drops x86 emulation from macOS, the mac client will die with it), and Linux users that used Wine to play League were thrown under the bus
Thank you yes that's exactly it and let's be real, I don't think even Valve really gives that much of a fuck about Linux users. It could well be they consider it fine to boot Linux off multiplayer games because they've seen how normie gamers are absolutely fine with putting literal spyware on their machines and they know more privacy oriented Linux users will simply avoid these games anyway when they see them or stubbornly resist.
It's not even going to be worth it for a lot of Linux users at this rate to be running dual boot Windows which I know a lot of them do because then simply having windows on your machine opens you up to all sorts of crap.
Mind you, something I've been thinking about would be very unpopular with the trading addicts on these games. Many of them will be cheating to game the system so if it were me I'd disable the entire system entirely and make it so players could only directly buy skins from now on and speculators couldn't make money off it by trying to cheat their way through the system. It wouldn't get rid of the cheating entirely but it would certainly get rid of the incentive because I think that's where most of this stuff comes from.
Looking at CS:2 as well I'd been playing it recently out of boredom and with how retarded the players are generally I'm wondering how many of them really are bots looking to try and idle their way through the game in order to get case drops. It's already a thing on fortnite to do that so I don't see why it couldn't happen there too.
Steam Deck is a Linux device so I don't know how accurate the idea that Valve will be quick to throw it overboard is. Non-Steam Deck users are a side effect and not a goal, so, sure, no one cares about them specifically but they can't get fucked without Valve fucking themselves, too.
That said, with the leaderless chaos that is Valve's employees, that the left hand didn't know what the right hand is doing wouldn't be too much of a stretch.